Drop-pit mechanism for unwheeling locomotives



.J'une 15 1926. 1,588,783

E. D. TILLYER OPHTHALMIC LENS Filed August 2. 1922 2 Sheets-Sheet 1INVENTOR fig E. 0. TIL L YER )4? 1 3 6 a 9 'a' V. 0

ATTORNEY$ 3 8 8 8 1 RS W e m Q DT un Ew June 15 1926.

Filed August 2. 1922 2 Sheets-Sheet 2 INVENTOR E D. TILLYER BY H! M auraATTORNEYS Patented June 15, 1 926.

UNITED STATES PATENT OFFICE.

EDGAR D. TILLYER, OF SOUTHBRIDGE, MASSACHUSETTS, ASSIGNOB TO AMERICANOPTICAL COMPANY, OF SOUTHBRIDGE, MASSACHUSETTS, A VOLUNTARY ASSO-CIATION OF MASSACHUSETTS.

OPHTHALMIC LENS.

Application fled August 8, 1982. Serial lb. 579,205.

This invention relates to new and useful improvements in the manufactureof o hthalmic lenses and more particularly to w at is known in the artas bifocal lenses.

The main object of the present invention is the provision of novel meansfor manufacturing the button for a two part lens and wherein this buttonwhen fused into position in the main lens blank will form what is knownas a jumpless line of joinder between the button and the lens blank.

Another object of this invention resides in the construction of a buttonfor bifocal lenses wherein a portion of the button is formed of the sametype of glass as the body blank so that when the button is placed inposition and both the button and blank fused together, one part of thebutton will become invisible leaving the remaining portion of the buttonvisible and disposed in the proper position with respect to the mainblank.

A further object of this invention is the manufacture of buttons forbifocal lenses wherein the buttons are formed by taking two bars ofglass and an intermediate index of glass of different types, adheringthe parts with the proper curve intermediate the bars so that severalbuttons can be cut from a finished bar and the said buttons then shapedto conform to the concave surface of the recess in the main blank, afterwhich they are fused in place and ground down to the proper curvature.

In a great many cases the segment or button for a bifocal lens is formedof a single piece of glass but in a great many instances the segments orbuttons are formed of more than one piece of glass and as a rule theline of joinder between these two pieces remains visible to a certainextent and it is, therefore, one of the objects of my invention toprovide a connection between the two pieces whereby to reduce thevisibilit of the line of joinder to a minimum and a so to reduce thereflection caused by joining two pieces of glass to form the button orsegment.

With the above and other objects in view the invention consists in thenovel features of construction, the combination and arrangement of partshereinafter more fully set io th, p t d ut in the as! shown in theaccompanying drawings. in which- Figure I is a perspective view of twobars of glass formed to the proper shape, in order to carry out myinvention.

Figure II is a transverse sectional view after the two bars of glasshave been secured to ether.

igure III is a side elevation of a single button cut from the finishedbar shown in Fi ure II.

igure IV is a side elevation of a button having one side rounded ofi toconform to the concave recess in the blank.

Fi re V is a sectional view of the blank showing the button in positionprior to grinding, and 1 Figure VI is a plan view of a finished ens.

Figure VII is an elevation of a lens blank psed in the manufacture of myimproved ens.

Figure VIII is a side elevation of a modified button or readin se mentused in conllrefiilon with the blan il ustrated in Figure Figure IX is afront elevation of the but ton shown in Figure VIII.

Figure X is a sectional view through the lens with the button in placeprior to grind- Figure XI is an elevation of the lens after being groundto the desired curvature.

Figure XII is a front elevation illustrating another form of button, and

igure XIII is a front elevation of a finished lens illustratin the useof the button shown in Figure XII.

In carrying out my invention I form two bars of glass generallyindicated by the numerals 1 and 2, the bar 1 being preferably of flintglass and provided upon one face with a rounded surface as at 3. The bar2 is preferably of crown glass having a concave face 4 which is adaptedto comate with the round or convex surface 3 of the bar 1 so that thetwo bars may be readily secured together by having the convex surface ofthe bar 1 fitted into the concave portion 4 of the bar 2 and adhered byheating the glass 's a soft ni g P nt It will be apparent that prior tothe formation of the curved surfaces 3 and 4 the bars are substantiallyrectangular shape in cross section. The surfaces 3 and 4 are then formedin one face of each of the bars and the two bars fixed together asillustrated in cross section in Figure II. In the construction of thecompleted bar shown in Figure 11 it is preferred to have the bar 1formed of flint lass while the bar 2 is preferably of crown glass.

After the bars 1 and 2 have been heated and adhered together to form theconstruction shown in Figure II, the bar is cut up into individual iecesas shown in F 1gure III, said pieces ing of the proper size inaccordance with the type of button to have formed therefrom. In FigureIV it will be noted that one face of the button has been ground away toform a convex surface 5 on one face of the button adapted to be fittedinto a concave recess 6 formed in the lens blank 7. In the constructionof the blank 7 it is preferred to have the same form of crown glass orof substantially the same type of glass as the bar 2.

After the button has been laced in position within the recess 6 the lankand button are heated to a fusing point, the portion 8 of the buttonbeing 0 the same material or same index of refraction as the button 7.It will be entirely invisible after the button has been fused onto theblank, leaving the lower portion 9 of the button visible with an upperline of curvature as at 10. This section 9 of the button is visible dueto the fact that it is of flint glass and of different index ofrefraction from the remaining portion of the button. It will be apparentthat by having this curved line 10 in the finished product and b havingthe portion 8 of the button forme of the same type of glass as the blankit will reduce to a minimum the line of joinder between the button 9 andthe main body of the blank.

In Figure VII I provide a blank 11 which is preferably of crown glasshaving the usual recess 12 for the reception of the reading portion orbutton which goes to make up the finished bifocal lens.

The button or segment which I have provided in this instance with anintermediate index is formed of three pieces of glass and in order toprovide a complete button for the purpose set forth above I utilize asection of crown glass indicated at 13 and a section of flint glass asat 14. As a general rule these two pieces are fused together to form thecompleted button to be fitted within the recess 12 and there is usuall acertain amount of visibility to the line 0 joinder between these twopieces of glass and in order to reduce this visibility to a minimum Ifuse between the sections 13 and 14 what will be known as anintermediate section. In other words,

we will take for exam is the fact that the section 13 is 1.52, ansection 14 is 1.62, therefore the intermediate section will be 1.57 andmay be either of crown or flint glass, the only necessary requirementbeing that the section 15 be an intermediate as set forth above.

In joining the sections 13 and 14: it will be ap arent that either astraight line or curve line of joinder may be used, the two differenttypes being fully illustrated in the accompanyin drawings. After thethree sections of t e button have been securely fused together one sideof the ,button is ground off as illustrated in Figure X and then lacedwithin the recess 12 of the blank 11 w are it then can be ground downtogether with the blank, to the proper prescri tion.

alling attention to Figures XI and XII it will be noted that in oneinstance the upper line of the section 14 is disposed oira curve whilethe other instance is substantiallgl horizontal, this line beingdetermined by t e line of connection between the sections 13 and 14 whenfused together.

Attention is called to the fact that as section 13 is formed of crownglass the same as the main blank 11, this section will be renderedinvisible when fused under the main blank thus leaving the flint section14 visible for the reading portion of the lens.

From the above descriptions taken in connection with the accompanyingdrawings it will be apparent that by using an intermediate sectionbetween the two sections of glass which make up the button or readingportion of the lens, the vision of the line of joinder between the twosections of glass will be reduced to a minimum, and also reduces thereflection caused by the joint between the two sections.

It will be apparent from the above that I have provided a new and novelmanner for forming bifocal lenses and one wherein the button for thelens can be manufactured and placed upon the market at a comparativelysmall cost. It will also be apparent that the construction of the buttontogether with the fitting of the same onto the lens blank is extremelysimple in construction and can be readily carried out.

I claim: 1. The process of making a blank for a reading portion of afused multifocal lens, comprising surfacing one face of an elongated barof glass, surfacing one face of another elongated bar of lass ofdifferent index of refraction from t e first bar, fusing the two barstogether on their surfaced faces and separating the fused bar into aplurality of sections on a line substantially normal to thefused faces,and of a thickness requisite to form a single blank for thereadingportion of a. fused multifocal lens.

2. The process of making a blank for the reading portion of a fusedmultifocal lens, comprising surfacing one face of an elongated bar ofglass, surfacing one face of another elongated bar of glass of differentindex of refraction from the first, surfacing the two opposite faces ofa third elongated bar of glass of index of refraction intermediate ofthe first two, fusing the three bars together on their surfaced faces,and separating the fused bar into a plurality of sections on linessubstantially normal to the surfaced faces and of a thickness requisiteto form a single blank for the reading portion of a fused multifocallens.

3. The process of maki a blank for the reading portion of a fusemultifocal lens, comprising surfacing one face of an elongated bar ofglass to a convex curve, surfacing another elongated bar of glass ofdifferent index of refraction from the first to a concave curvesubstantially contrageneric with the first curve, fusing the two barstogether on their curved surfaced faces, and separating the fused barinto a plurality of sections on lines substantially normal to thesurfaced faces of a thickness requisite to form a single blank for thereading portion of a fused multifocal lens.

EDGAR D. TILLYER.

